examples/draganddrop/draggabletext/dragwidget.cpp
author Eckhart Koeppen <eckhart.koppen@nokia.com>
Mon, 19 Apr 2010 10:15:19 +0300
branchRCL_3
changeset 9 b5b118452c7d
parent 4 3b1da2848fc7
permissions -rw-r--r--
a8c775f23625952540b5349744722bcb9e37de45

/****************************************************************************
**
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include <QtGui>

#include "draglabel.h"
#include "dragwidget.h"

DragWidget::DragWidget(QWidget *parent)
    : QWidget(parent)
{
    QFile dictionaryFile(":/dictionary/words.txt");
    dictionaryFile.open(QIODevice::ReadOnly);
    QTextStream inputStream(&dictionaryFile);

    int x = 5;
    int y = 5;

    while (!inputStream.atEnd()) {
        QString word;
        inputStream >> word;
        if (!word.isEmpty()) {
            DragLabel *wordLabel = new DragLabel(word, this);
            wordLabel->move(x, y);
            wordLabel->show();
            wordLabel->setAttribute(Qt::WA_DeleteOnClose);
            x += wordLabel->width() + 2;
            if (x >= 195) {
                x = 5;
                y += wordLabel->height() + 2;
            }
        }
    }

    QPalette newPalette = palette();
    newPalette.setColor(QPalette::Window, Qt::white);
    setPalette(newPalette);

    setAcceptDrops(true);
    setMinimumSize(400, qMax(200, y));
    setWindowTitle(tr("Draggable Text"));
}

void DragWidget::dragEnterEvent(QDragEnterEvent *event)
{
    if (event->mimeData()->hasText()) {
        if (children().contains(event->source())) {
            event->setDropAction(Qt::MoveAction);
            event->accept();
        } else {
            event->acceptProposedAction();
        }
    } else {
        event->ignore();
    }
}

void DragWidget::dropEvent(QDropEvent *event)
{
    if (event->mimeData()->hasText()) {
        const QMimeData *mime = event->mimeData();
        QStringList pieces = mime->text().split(QRegExp("\\s+"),
                             QString::SkipEmptyParts);
        QPoint position = event->pos();
        QPoint hotSpot;

        QList<QByteArray> hotSpotPos = mime->data("application/x-hotspot").split(' ');
        if (hotSpotPos.size() == 2) {
            hotSpot.setX(hotSpotPos.first().toInt());
            hotSpot.setY(hotSpotPos.last().toInt());
        }

        foreach (QString piece, pieces) {
            DragLabel *newLabel = new DragLabel(piece, this);
            newLabel->move(position - hotSpot);
            newLabel->show();
            newLabel->setAttribute(Qt::WA_DeleteOnClose);

            position += QPoint(newLabel->width(), 0);
        }

        if (event->source() == this) {
            event->setDropAction(Qt::MoveAction);
            event->accept();
        } else {
            event->acceptProposedAction();
        }
    } else {
        event->ignore();
    }
    foreach (QObject *child, children()) {
        if (child->inherits("QWidget")) {
            QWidget *widget = static_cast<QWidget *>(child);
            if (!widget->isVisible())
                widget->deleteLater();
        }
    }
}

void DragWidget::mousePressEvent(QMouseEvent *event)
{
    QLabel *child = static_cast<QLabel*>(childAt(event->pos()));
    if (!child)
        return;

    QPoint hotSpot = event->pos() - child->pos();

    QMimeData *mimeData = new QMimeData;
    mimeData->setText(child->text());
    mimeData->setData("application/x-hotspot",
                      QByteArray::number(hotSpot.x())
                      + " " + QByteArray::number(hotSpot.y()));

    QPixmap pixmap(child->size());
    child->render(&pixmap);

    QDrag *drag = new QDrag(this);
    drag->setMimeData(mimeData);
    drag->setPixmap(pixmap);
    drag->setHotSpot(hotSpot);

    Qt::DropAction dropAction = drag->exec(Qt::CopyAction | Qt::MoveAction, Qt::CopyAction);

    if (dropAction == Qt::MoveAction)
        child->close();
}